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I downloaded and tried that theme and it worked just fine for me.
Do Option 2 of this tutorial SFC /SCANNOW Command - System File Checker
it will not harm any data or programs you have installed it will try to repair any system files that have become corrupt.
Now use one of these two tutorials on how to enable custom themes.
The first one is just a service and you do not need to patch system files with it, I use it all the time. Enabling Custom Themes - Windows 7
Or Theme - How to Apply Custom Themes
Make sure you have both the theme folder and the .theme file (See screenshot) in C:\Windows\Resources\Themes
If you need more help let me know.